The present invention generally relates to a balancing weight used to balance a rotating shaft and a method of applying the balancing weight to a shaft.
Typically, steel or aluminum balance weights for drive shafts are welded onto skirts on weld yokes at the end of the drive shaft. The heat of the welding process can cause the drive shaft to distort, thereby causing the drive shaft to require re-balancing after cooling. The ends of the drive shaft are not the optimal locations to place the balancing weights, however welding the balancing weights to the thin walled portions of the drive shaft is more difficult than welding the balancing weights to the skirts at the ends of the drive shaft. Using an adhesive to attach the balancing weights to the drive shaft would eliminate the distortion due to welding, reduce the cost of the weights and eliminate the skirts on the weld yokes, thereby lowering the weight of the drive shaft. Unfortunately, the curing time for most suitable adhesives is too long for normal production cycle times. Some adhesives can be cured much faster by exposing the adhesive to ultra-violet light. These adhesives can cure in as little as ten seconds, however only the adhesive that is directly exposed to the ultra-violet light cures, thereby only providing a secure bond around the edges of the weight where the adhesive oozes out from under the weight. The remaining adhesive under the main body of the weight, which is not exposed to the ultra-violet light can take up to 24 hours to cure properly, even with a chemical activator. Therefore, there is a need for an improved balancing weight and method of attaching the balancing weight to a rotating cylindrical shaft.